Communities and microhabitats of living benthic foraminifera from the tropical East Atlantic

DOI

Living (Rose Bengal stained) benthic foraminifera were collected with a multicorer from six stations between 2°N and 12°S off West Africa. The foraminiferal communities in the investigated area reflect the direct influence of different productivity regimes, and are characterized by spatially and seasonally varying upwelling activity. At five stations, foraminiferal abundance coincides well with the gradient of surface productivity. However, at one station off the Congo River, the influence of strong fresh water discharge is documented. Although this station lies directly in the center of an upwelling area, foraminiferal standing stocks are surprisingly low. It is suggested that the Congo discharge may induce a fractionation of the organic matter into small and light particles of low nutritional content, by contrast to the relatively fast-sinking aggregates found in the centers of high productivity areas.Quality and quantity of the organic matter seem to influence the distribution of microhabitats as well. The flux of organic carbon to the sea-floor controls the sequence of degradation of organic matter in sediment and the position of different redox fronts. The vertical foraminiferal stratification within sediment closely parallels the distribution of oxygen and nitrate in porewater, and reflects different nutritive strategies and adaptation to different types of organic matter. The epifauna and shallow infauna colonize oxygenated sediments where labile organic matter is available. The intermediate infauna (M. barleeanum) is linked to the zone of nitrate reduction in sediments where epifaunal and shallow infaunal species are not competitive anymore, and must feed on bacterial biomass or on metabolizable nutritious particles produced by bacterial degradation of more refractory organic matter. The deep infauna shows its maximum distribution in anoxic sediments, where no easily metabolizable organic matter is available.

Supplement to: Licari, Laetitia; Schumacher, Stefanie; Wenzhöfer, Frank; Zabel, Matthias; Mackensen, Andreas (2003): Communities and microhabitats of living benthic foraminifera from the tropical East Atlantic: impact of different productivity regimes. Journal of Foraminiferal Research, 33(1), 10-31

Identifier
DOI https://doi.org/10.1594/PANGAEA.728238
Related Identifier https://doi.org/10.2113/0330010
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.728238
Provenance
Creator Licari, Laetitia; Schumacher, Stefanie; Wenzhöfer, Frank; Zabel, Matthias; Mackensen, Andreas
Publisher PANGAEA
Publication Year 2003
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 13 datasets
Discipline Earth System Research
Spatial Coverage (6.720W, -11.903S, 13.073E, 2.678N); Eastern Niger fan; off northern Gabun; off Gabun; northern Congo fan; off Angola
Temporal Coverage Begin 1998-02-26T01:05:00Z
Temporal Coverage End 1998-03-10T14:12:00Z